Many social critics wag their fingers at what they perceive to be frivolous luxury spending. But that misses the point that consumption norms are local. It's not just the rich who spend more when they get more money. Everyone else does, too. The mansions of the rich may seem over the top to people in the middle, but the same could be said of middle-class houses as seen by most of the planet's seven billion people.

Economics, as it is often taught today, portrays us as homo economicus-someone who doesn't vote in presidential elections, doesn't return lost wallets, and doesn't leave tips when dining out of town. Julie Nelson reminds us that most people aren't really like that. She helps point the way to a richer, more descriptive way of thinking about economic life.

The most glaring deficiency in traditional economic models is that they completely ignore the role of context in evaluation.

John Stuart Mill believed that the only acceptable reason for government to limit a person's liberty was to prevent him from causing unacceptable harm to others. Mill was not a libertarian, but many libertarians are quick to cite this principle when arguing against a regulation that they oppose. And I believe most thoughtful libertarians are prepared to embrace something fairly close to Mill's harm principle. But accepting that principle implies accepting many of the institutions of the modern welfare state that libertarians have vigorously opposed in the past, such as safety regulation.

The private sector is first of all much larger than the public sector. The waste we see in that sector does not result from the fact that people spend their money carelessly. Mostly, it occurs because what one family must spend to achieve its goals often depends heavily on what other families spend.

As economists have long noted, the puzzle is not that so few people vote, it's that so many do. After all, no individual's vote has ever tipped the balance in a presidential election.

We're in a classic demand-shortfall recession. There aren't enough jobs because total spending is too low. Consumers won't lead the way because they're busy paying down debt and are fearful they'll lose their jobs, if they haven't already. Businesses, which are currently sitting on mountains of cash, won't spend either, because they already have sufficient capacity to produce more than people are willing to buy.